1. Technical Field
The present disclosure relates to an ink pattern printing apparatus, and more particularly, to an ink pattern printing apparatus including a blade, a method of forming an ink pattern using the ink pattern printing apparatus, and a method of manufacturing a liquid crystal display using the ink pattern printing apparatus.
2. Discussion of the Related Art
Electronic devices can be made lighter, smaller and of higher density using fine patterns such as, for example, micropatterns. In a liquid crystal display, micropatterns for forming components such as wires, filters and spacers can be made through a variety of pattern formation techniques.
In a liquid crystal display, spacers are interposed between two opposing substrates to maintain a cell gap between the two substrates. The spacers can be bead spacers and column spacers. A dispersing method can be used for forming the bead spacers, and a patterning method can be used for forming the column spacers. The dispersing method for forming bead spacers is simpler as compared to the patterning method for forming column spacers. However, beads dispersed at pixel regions of a liquid crystal display decrease an aperture ratio and cause light leakage. According to the patterning method, a decrease of the aperture ratio can be prevented since the column spacers can be accurately formed at desired positions. However, the patterning method involves a more complex photolithographic process. Further, micropatterns formed by photolithography can be overetched due to, for example, an etching solution or an etching gas.
An organic film comprising a photosensitive material can be used for the exposure and development processes. However, this method is not cost effective because only a small portion of the organic film coated on the entire surface of a substrate is used.
An alternative approach is a printing method using, for example, recesses having the same pattern as a spacer pattern formed in a printing plate, and spacer-containing ink filled in the recesses. Residual ink outside the recesses is removed using a blade, and the resultant ink pattern is transferred to a substrate. With the printing method, position adjustment can be performed more precisely and process costs are lower compared to the dispersing and the patterning methods. However, as the size of a substrate increases, the size of the blade also increases. With larger-sized blades, abrasion due to a physical contact between the substrate and the blade can occur during the removal of the residual ink, rendering the surface of the blade uneven. An uneven blade may not completely remove the residual ink on the printing plate, thereby causing inaccurate printing of an ink pattern.